Power source derating component protection system

ABSTRACT

A protection system is provided for a work machine with a power source. At least one sensor is configured to monitor a fluid parameter of a work machine system external to the power source. The sensor is further configured to produce a signal indicative of a value of the fluid parameter. The component protection system has a control module in communication with the at least one sensor, the control module being configured to derate a power source output base upon the value of the fluid parameter.

TECHNICAL FIELD

The present disclosure relates generally to a component protectionsystem and, more particularly, to a component protection system thatimplements power source derating.

BACKGROUND

A work machine may include many different fluid systems having multiplecomponents within each system. Although single component failures withinthe various systems may not be completely preventable, continuedoperation of the work machine under component failure conditions couldresult in complete fluid system failure. Engine protection systems havebeen implemented that monitor engine fluid conditions and implementroutines to protect the engine when the fluid conditions of the engineare not within acceptable ranges.

One such protection system is described in U.S. Pat. No. 5,070,832 (the'832 patent) to Hapke et al. The '832 patent teaches an engineprotection system that monitors various engine fluid parameters andcompares the parameters to limit values. If a fluid fault conditionexists, the engine performance is derated to prevent catastrophicfailure of the engine.

Although the engine protection system of the '832 patent may protect theengine of a work machine when the engine fluid operating conditionsexceed acceptable limits, it may do nothing to protect work machinesystems that are external to the engine. In particular, because thefluid conditions monitored by the engine protection system of the '832patent are not related to fluid conditions of work machine systemsexternal to the engine, these external systems may continue to operateto the point of complete system failure after a single componentmalfunction without detection of a fluid condition abnormality and/orintervention by the engine protection system.

The disclosed component protection system is directed to overcoming oneor more of the problems set forth above.

SUMMARY OF THE INVENTION

In one aspect, the present disclosure is directed to a componentprotection system for a work machine that has a power source. Thecomponent protection system includes at least one sensor configured tomonitor a fluid parameter of a work machine system external to the powersource and to produce a signal indicative of a value of the fluidparameter. The component protection system also includes a controlmodule in communication with the at least one sensor, the control modulebeing configured to derate a power source output based upon the value ofthe fluid parameter.

In another aspect, the present disclosure is directed to a method ofprotecting a work machine system external to a work machine powersource. The method includes monitoring a fluid parameter associated withthe work machine system and derating an output of the work machine powersource base upon a value of the fluid parameter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic illustration of an exemplary disclosedcomponent protection system; and

FIG. 2 is an exemplary process flow chart for the component protectionsystem of FIG. 1.

DETAILED DESCRIPTION

FIG. 1 illustrates an exemplary work machine 10. Work machine 10 may bea fixed or mobile machine that performs some type of operationassociated with an industry such as mining, construction, farming,transportation, or any other industry known in the art. For example,work machine 10 may be an earth moving machine such as a dozer, aloader, an excavator, a motor grader, a dump truck, or any other earthmoving machine. Work machine 10 may alternately be a generator set, apump, a marine vessel, a passenger vehicle, or any other suitableoperation-performing work machine. Work machine 10 may include a powersource 12, a transmission 14, a hydraulic system 16, and a componentprotection system 18.

Power source 12 may include an internal combustion engine such as, forexample, a diesel engine, a gasoline engine, a natural gas engine, orany other engine apparent to one skilled in the art. Power source 12may, alternately, include another source of power such as a furnace, abattery, a fuel cell, or any other source of power known in the art. Inone embodiment, power source 12 may be a four cylinder diesel enginehaving one fuel injector 20 per cylinder. It is contemplated that powersource 12 may have a greater or lesser number of cylinders and/or adifferent number of fuel injectors 20 per cylinder.

Transmission 14 may be configured to transmit power from power source 12to an output device (not shown) at a range of output speed ratios.Transmission 14 may be a hydraulic transmission, a mechanicaltransmission, a hydro-mechanical transmission, or any other suitabletransmission. The output device may include such devices as a groundengaging device, a pump, a generator, a propeller, or any other outputdevice known in the art. An input drive member such as, for example, acountershaft 22, may connect power source 12 to transmission 14.Transmission 14 may also include an output driven member such as, forexample, an output shaft 24 connecting transmission 14 to the outputdevice. In this manner, power generated by power source 12 may betransmitted through output shaft 24 to the output device. It iscontemplated that transmission 14 may alternately transmit power frompower source 12 to the output device at only a single output speedratio.

Hydraulic system 16 may include components configured to hydraulicallytransfer power from power source 12 to one or more work tools (notshown) in response to an operator input. Specifically, hydraulic system16 may include a pump 26 configured to pressurize a fluid directed toone or more hydraulic cylinders 28.

Pump 26 may be a variable displacement pump, a fixed displacement pump,a variable flow pump, or any other source of pressurized fluid known inthe art. Pump 26 may be drivably connected to power source 12 via aninput drive member such as, for example, a countershaft 30. Pump 26 mayconvert an input rotation of countershaft 30 into an output ofpressurized fluid. In this manner, mechanical power generated by powersource 12 may be converted to fluid power.

Hydraulic cylinder 28 may be fluidly connected to pump 26 via a fluidpassageway 32 and may function to actuate the work tool. In particular,hydraulic cylinder 28 may be supplied with the pressurized fluid frompump 26 to cause a piston assembly (not shown) within hydraulic cylinder28 to displace within a tube (not shown) of hydraulic cylinder 28,thereby increasing an effective length of hydraulic cylinder 28.Hydraulic cylinder 28 may also be connected to a fluid drain (not shown)to cause the piston assembly to displace within the tube to decrease theeffective length of hydraulic cylinder 28. In this manner, the expansionand retraction of hydraulic cylinder 28 may convert the fluid power frompump 26 to mechanical power that assists the movement of the work tool.It is contemplated that hydraulic cylinder 28 may be omitted, ifdesired, and a different hydraulic device may be fluidly coupled to pump26.

Component protection system 18 may be in communication with transmission14, hydraulic system 16, and power source 12. Specifically, componentprotection system 18 may include a control module 34 in communicationwith a transmission sensor 36 via a communication line 38, with ahydraulic system sensor 40 via a communication line 42, and withinjectors 20 of power source 12 via a communication line 44.

Control module 34 may include a microprocessor with a means for storingand comparing information, and for controlling an operation of powersource 12. Control module 34 may be embodied in a single microprocessoror multiple microprocessors. Numerous commercially availablemicroprocessors can be configured to perform the functions of controlmodule 34. It should be appreciated that control module 34 could readilybe embodied in a general work machine microprocessor capable ofcontrolling numerous work machine functions. Control module 34 mayinclude any means for storing, comparing, and controlling such as amemory, one or more data storage devices, or any other components thatmay be used to run an application. Furthermore, although aspects of thepresent disclosure may be generally described as being stored in memory,one skilled in the art will appreciate that these aspects can be storedon or read from types of computer-related products or computer-readablemedia such as computer chips and secondary storage devices, includinghard disks, floppy disks, optical media, CD-ROM, or other forms of RAMor ROM. Various other known circuits may be associated with controlmodule 34, including power supply circuitry, signal-conditioningcircuitry, solenoid driver circuitry, communication circuitry, and otherappropriate circuitry.

Transmission sensor 36 may be configured to sense a fluid parameter oftransmission 14 and to generate a signal having a value indicative ofthe fluid parameter. For example, transmission sensor 36 may beconfigured to sense a fluid parameter of a fluid provided to a clutch(not shown) within transmission 14, to sense a fluid parameter of afluid within a sump (not shown) of transmission 14, to sense a fluidparameter of a fluid directed between a pump (not shown) and a motor(not shown) within transmission 14, or to sense a fluid parameter of anyother suitable fluid within transmission 14. The fluid parameter sensedby transmission sensor 36 may include, for example, a pressure, atemperature, a viscosity, or any other transmission fluid parameterknown in the art.

Hydraulic system sensor 40 may be configured to sense a parameter of thefluid directed between pump 26 and hydraulic cylinder 28 withinhydraulic system 16, to sense a fluid parameter of a fluid within a sump(not shown) of hydraulic system 16, or to sense a fluid parameter of anyother suitable fluid within hydraulic system 16. The fluid parametersensed by hydraulic system sensor 40 may include, for example, apressure, a temperature, a viscosity, or any other hydraulic systemfluid parameter known in the art.

Control module 34 may configured to change an operation of power source12. Operational changes of power source 12 may include derating anoutput of power source 12 such as, for example, an output torque and/oran output speed. Derating an output of power source 12 may includelowering a maximum output of power source 12 over an entire operatingrange of power source 12. For example, a maximum output torque may belowered over a range of output speeds by changing fuel deliverycharacteristics of fuel injectors 20. Similarly, a maximum output speedmay be lowered over a range of transmission output ratios. The fueldelivery characteristics available for modification may include a fueldelivery amount, a fuel delivery timing, and any other fuel deliverycharacteristics known in the art.

Control module 34 may change the operation of power source 12 inresponse to signals from transmission sensor 36 and/or hydraulic systemsensor 40. By means of example, control module 34 may include a table ofderate percent values stored in the memory of control module 34. As willbe described in more detail in the following section, these deratepercent values may be related to values of the signals produced bytransmission sensor 36 and/or hydraulic system sensor 40. It iscontemplated that the table may be omitted, if desired, and that controlmodule 34 may alternately derate power source 12 based upon one or morepredetermined equations as functions of the signal values fromtransmission sensor 36 and/or hydraulic system sensor 40.

FIG. 2 illustrates a flowchart 46 depicting an exemplary method foroperating component protection system 18. Flowchart 46 will be describedin further detail in the following section.

INDUSTRIAL APPLICABILITY

The disclosed component protection system finds potential application inany power system where it is desirable to protect components of a workmachine auxiliary system that is external to a main power source anddriven by the main power source. Specifically, when a sensed fluidparameter value of an auxiliary system is indicative of a componentfailure within the auxiliary system, an operation of the main powersource may be controlled to prevent the power source from driving theauxiliary system to further detriment.

Referring to FIG. 2, when component protection system 18 is inoperation, the value of one or more fluid parameters within transmission14 and/or hydraulic system 16 may be continuously sensed and comparedwith predetermined acceptable ranges for the particular fluid parameters(step 100). It is also contemplated that the value of one or more fluidparameters within transmission 14 and/or hydraulic system 16 may bechecked at predetermined time intervals. Component protection system 18may then determine if the values of the fluid parameters are within thepredetermined acceptable ranges (step 110). If the value of the fluidparameters are within the predetermined acceptable ranges, componentprotection system 18 may continue to sense the fluid parameters withoutchanging an output of power source 12 (step 100).

However, if one or more of the fluid parameter values deviate from thepredetermined acceptable ranges, the magnitude of the deviation may bequantified and compared to the derate table stored in the memory ofcontrol module 34 to determine an appropriate derate percent that willprotect transmission 14 and/or hydraulic system 16 from further damage(step 120). The derate table may include specific derate percent valuesthat correspond with specific parameter values. Appropriate deratepercent values, which correspond with parameter values that are notlisted in the table, may be determined through, for example, linearlyinterpolation or extrapolation. It is contemplated that the appropriatederate percents for parameter values not listed in the derate table may,alternately, be non-linearly interpolated or extrapolated according toone or more predetermined equations. It is further contemplated that allappropriate derate percents may be calculated using a desired formula.

Once the derate percent value has been determined, this value may beapplied to power source 12 (step 130). As described above, the deratemay be implemented by controlling a fuel injection quantity and/or fuelinjection timing of injectors 20. It is contemplated that prior toderating operation of power source 12, a warning consisting of, forexample, the actuation of a warning lamp and or a warning signal may beinitiated when the values of the sensed parameters have exceeded thepredetermined acceptable ranges, but have not yet exceeded a minimumderate threshold. During and after derate, control module 34 maycontinue to sense the fluid parameters of transmission 14 and/orhydraulic system 16 to determine if further action is required (step100).

Regardless of the magnitude of deviation beyond the predeterminedacceptable range, the maximum amount of derate may be limited to amaximum output under non-derated operation. In one example, the maximumamount of derate may be limited to a maximum derate of 50% of the powersource maximum output. In this manner, sufficient power source outputmay be maintained that ensures safe operation of work machine 10 and/orthat ensures the capability for the work machine 10 to return to aservice bay for repair (“limp-home capacity”).

Several advantages are realized because the operation of power source 12may be changed in response to a sensed parameter of a fluid systemexternal to power source 12. A minor component failure that can becost-effectively repaired may be quickly brought to the attention of awork machine operator. In addition, automatic reduction of the powersource driving force and/or speed that might otherwise contribute tosystem-wide failure, may result in the failed component have a limiteddamaging effect on the associated system.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the component protectionsystem of the present disclosure. Other embodiments of the componentprotection system will be apparent to those skilled in the art fromconsideration of the specification and practice of the inventiondisclosed herein. It is intended that the specification and examples beconsidered as exemplary only, with a true scope of the invention beingindicated by the following claims and their equivalents.

1. A protection system for a work machine having a power source,comprising: at least one sensor configured to monitor a fluid parameterof a work machine system external to the power source, and to produce asignal indicative of a value of the fluid parameter, wherein the workmachine system is one of a hydraulic system that actuates at least onework tool and a transmission; and a control module in communication withthe at least one sensor, the control module being configured toselectively derate a power source output based upon the value of thefluid parameter when the value of the fluid parameter is indicative of acomponent failure within the work machine.
 2. The protection system ofclaim 1, wherein the work machine system is a transmission and the fluidparameter is a pressure of a fluid within the transmission.
 3. Theprotection system of claim 1, wherein the work machine system is atransmission and the fluid parameter is a temperature of a fluid withinthe transmission.
 4. The protection system of claim 1, wherein the workmachine includes at least one work tool, the work machine system being ahydraulic system that actuates the at least one work tool and the fluidparameter is a pressure of a fluid within the hydraulic system.
 5. Theprotection system of claim 1, wherein the work machine includes at leastone work tool, the work machine system being a hydraulic system thatactuates the at least one work tool and the fluid parameter is atemperature of a fluid within the hydraulic system.
 6. The protectionsystem of claim 1, wherein the output is a speed of the power source. 7.The protection system of claim 1, wherein the output is a torque of thepower source.
 8. The protection system of claim 1, wherein the output isderatable to a maximum derate of 50% of full output.
 9. The protectionsystem of claim 1, wherein the control module includes a map having atable of parameter values and corresponding desired derate values. 10.The protection system of claim 1, wherein the control module derates theoutput in response to the value being outside of a predetermined range.11. The protection system of claim 1, wherein the control module isfurther configured to actuate a warning when the value of the fluidparameter exceeds a predetermined acceptable range, but has not yetexceeded a minimum derate threshold.
 12. A method of protecting a workmachine system external to a work machine power source, the methodcomprising: monitoring a fluid parameter associated with the workmachine system, wherein the work machine system is one of a hydraulicsystem that actuates at least one work tool and a transmission; andderating an output of the work machine power source based upon a valueof the fluid parameter when the value of the fluid parameter isindicative of a component failure within the work machine.
 13. Themethod of claim 12, wherein the work machine system is a transmissionand monitoring a fluid parameter includes monitoring a pressure of afluid within the transmission.
 14. The method of claim 12, wherein thework machine system is a transmission and monitoring a fluid parameterincludes monitoring a temperature of a fluid within the transmission.15. The method of claim 12, wherein the work machine includes at leastone work tool, the work machine system being a hydraulic system thatactuates the at least one work tool and monitoring a fluid parameterincludes monitoring a pressure within the hydraulic system.
 16. Themethod of claim 12, wherein the work machine includes at least one worktool, the work machine system being a hydraulic system that actuates theat least one work tool and monitoring a fluid parameter includesmonitoring a temperature within the hydraulic system.
 17. The method ofclaim 12, wherein derating an output includes derating a speed of thepower source.
 18. The method of claim 12, wherein derating an outputincludes derating a torque of the power source.
 19. The method of claim12, wherein derating the output is in response to the value beingoutside of a predetermined range.
 20. The method of claim 12, whereinderating the output includes derating the output to a maximum derate of50% of full output.
 21. The method of claim 12, further including:comparing the value of the fluid parameter to a derate map stored in amemory of a control module associated with the work machine; andderating the output according to a relationship of the value of thefluid parameter and a derate value.
 22. The method of claim 12, furtherincluding actuating a warning when the value of the fluid parameterexceeds a predetermined acceptable range, but has not yet exceeded aminimum derate threshold.
 23. A work machine, comprising: a powersource; a fluid system external to the power source and drivablyconnected to the power source; and a protection system having: at leastone sensor configured to monitor a fluid parameter of a work machinesystem external to the power source and to produce a signal indicativeof a value of the fluid parameter, wherein the work machine system isone of a hydraulic system that actuates at least one work tool and atransmission; a control module in communication with the at least onesensor, the control module being configured to selectively derate apower source output based upon the value of the fluid parameter when thevalue of the fluid parameter is indicative of a component failure withinthe work machine.
 24. The work machine of claim 23, wherein the workmachine system is a transmission and the fluid parameter is at least oneof a pressure and a temperature of a fluid within the transmission. 25.The work machine of claim 23, wherein the work machine includes at leastone work tool, the work machine system being a hydraulic system thatactuates the at least one work tool, and the fluid parameter is apressure of a fluid within the hydraulic system.
 26. The work machine ofclaim 23, wherein the work machine includes at least one work tool, thework machine system being a hydraulic system that actuates the at leastone work tool, and the fluid parameter is a temperature of a fluidwithin the hydraulic system.
 27. The work machine of claim 23, whereinthe output is at least one of a speed and a torque of the power source.28. The work machine of claim 23, wherein the output is derated to amaximum derate of 50% of full output.
 29. The work machine of claim 23,wherein the control module includes a map having a table of parametervalues and corresponding desired derate values.
 30. The work machine ofclaim 23, wherein the control module derates the output in response tothe value being outside of a predetermined range.
 31. The work machineof claim 23, wherein the control module is further configured to actuatea warning when the value of the fluid parameter exceeds a predeterminedacceptable range, but has not yet exceeded a minimum derate threshold.